[windows] [build-hook] Logging is incomplete/inaccurate when running with CBuilder #61980
Description
Information
- Dart 3.10.0 (stable) (Thu Nov 6 05:24:55 2025 -0800) on "windows_x64"
- on windows / "Windows 11 Famille" 10.0 (Build 26200)
I'm trying to make a custom package using Dart FFI related features.
Dependencies
- hooks: ^1.0.0
- code_assets: ^1.0.0
- native_toolchain_c: ^0.17.3
Description:
I've defined a custom wrapper to create a dynamic library on top of Intel XED. I'm only trying on Windows x64 for now. Outside of Dart/Build Hook workflow, I built a xed.lib.
I copy the static library (xed.lib) inside my hook runner. In the example below, I purposely forgot to give the path to include headers for xed (while my code does #include <xed/xed-interface.h>).
Actual behavior
I execute dart run and get logs in stderr.txt and in the console about cl.exe (from MSVC) failing with a ProcessException. But there is nothing related to cl.exe logs output that could help me understand what went wrong.
Expected behavior
It should correctly output the entire stdout/stderr of the process being run (cl.exe).
If I run the cl.exe command myself (generated by CBuilder), it will show an error about the header of xed not present (missing -I declaration for xed/xed-interface.h).
hook/build.dart
void main(List<String> args) async {
await build(args, (input, output) async {
final packageName = input.packageName;
// ... copy `xed.lib` in `<output-dir>/vendors` ...
final builder = CBuilder.library(
name: packageName,
assetName: "src/$packageName.dart",
sources: ["src/main.cpp"],
includes: [
"src",
// "src/vendors/xed/kits/latest/include", // absent on purpose
],
linkModePreference: LinkModePreference.dynamic,
libraries: ["xed"],
libraryDirectories: ["vendors"],
);
await builder.run(input: input, output: output);
});
}Additional notes
The following may not be directly related (in case you wonder about building xed.lib outside of Dart Build Hook feature):
I first intended to directly clone Intel XED repositories (xed + mbuild), and build it as a shared library to import symbols directly (with build.dart).
Without Build Hook workflow, I can build the shared library without issues (MSVC + Python3).
With Build Hook, it failed when using Process.run to execute python mfile.py --shared (which is the build system used for Intel XED). Whether I was using runInShell, using python as the executable (absolute path), or running a shell (which would then execute the python command) it was always failing. Perhaps it works on other platforms (not Windows).